Coated articles are known in the art for use in window applications such as insulating glass (IG) window units, vehicle windows, monolithic windows, and/or the like. In certain example instances, designers of coated articles often strive for a combination of high visible transmission, substantially neutral color, low emissivity (or emittance), low sheet resistance (Rs), low U-values in the context of IG window units, and/or low specific resistivity. High visible transmission and substantially neutral color may permit coated articles to be used in applications where these characteristics are desired such as in architectural or vehicle window applications, whereas low-emissivity (low-E), low sheet resistance, and low specific resistivity characteristics permit such coated articles to block significant amounts of IR radiation so as to reduce for example undesirable heating of vehicle or building interiors.
Low-E coatings having at least one silver based IR reflecting layer are known in the art. For example, see U.S. Pat. Nos. 5,344,718, 6,576,349, 8,945,714, 9,371,684, 9,028,956, 9,556,070, 8,945,714, 9,028,983, which are all hereby incorporated herein by reference. Low-E coatings on glass are widely used in commercial and residential buildings to save energy. The double Ag low-E coating is a dominant low-E product due to its excellent low emissivity properties and excellent control of solar heat gain. While there are some durable low-E coatings in the market, their performances are sometimes poor especially with respect to undesirably low light-to-solar gain ratio (LSG) values of around 1.0 or less, because it is often difficult to achieve high visible transmission (Tvis) along with other desirable features in a low-E coating. The higher the LSG value, the more energy saved, so that high LSG values are desirable. LSG is calculated as Tvis/SHGC, where SHGC is according to NRFC 2001.
Certain example embodiments relate to a coated article including a coating comprising at least one silver (Ag) based infrared (IR) reflecting layer(s) that is provided adjacent to and contacting at least one contact layer of or including Ag, Ni and Cr. It has surprisingly been found that the provision of a contact layer(s) including at least Ag, Ni and Cr, directly over and contacting a silver-based IR reflecting layer, has been found to advantageously increase visible transmission (Tvis) of the low-E coating (compared to using a NiCr contact layer). Adding Ag to a NiCr based contact layer, directly contacting silver, has been surprisingly and unexpectedly found to increase visible transmission of the coating without sacrificing performance such as sheet resistance and/or emissivity. The provision of the contact layer(s) including at least Ag, Ni and Cr, directly over and contacting a silver-based IR reflecting layer, has also been found to advantageously increase solar factor (SF) and/or light-to-solar gain ratio (LSG) of the low-E coating, while not sacrificing emissivity and/or sheet resistance. The contact layer(s) including at least Ag, Ni and Cr may or may not be oxided, and is preferably a suboxide in certain example embodiments. The silver based IR reflecting layer, and adjacent contact layer(s) including at least Ag, Ni and Cr, are part of a low emissivity (low-E) coating, and may be sandwiched between at least transparent dielectric layers. Such low-E coating may be used in applications such as monolithic windows, insulated glass (IG) window units, and the like.
In an example embodiment of this invention, there is provided a coated article including a coating supported by a glass substrate, the coating comprising: a first dielectric layer on the glass substrate; an metallic or substantially metallic infrared (IR) reflecting layer comprising silver on the glass substrate located over at least the first dielectric layer; a protective contact layer comprising Ag, Ni and Cr on the glass substrate located over and directly contacting the IR reflecting layer comprising silver; a second dielectric layer on the glass substrate located over at least the first dielectric layer, the IR reflecting layer comprising silver, and the protective contact layer; wherein metal content of the protective contact layer comprising Ag, Ni and Cr comprises from about 5-40% Ag, from about 10-80% Ni, and from about 10-80% Cr (atomic %); and wherein the coating has a sheet resistance (Rs) of no greater than 11 ohms/square and a normal emissivity (En) of no greater than 0.2.
In an example embodiment of this invention, there is provided a method of making a coated article including a coating supported by a glass substrate, the method comprising: sputter depositing a first dielectric layer on the glass substrate; sputter depositing a metallic or substantially metallic infrared (IR) reflecting layer comprising silver on the glass substrate located over at least the first dielectric layer; sputter depositing a contact layer comprising Ag, Ni and Cr on the glass substrate located over and directly contacting the IR reflecting layer comprising silver; sputter depositing a second dielectric layer on the glass substrate located over at least the first dielectric layer, the IR reflecting layer comprising silver, and the contact layer; wherein metal content of the contact layer comprising Ag, Ni and Cr comprises from about 5-40% Ag, from about 10-80% Ni, and from about 10-80% Cr (atomic %); and wherein the coating has a sheet resistance (Rs) of no greater than 11 ohms/square and a normal emissivity (En) of no greater than 0.2.
The sputter depositing the contact layer comprising Ag, Ni and Cr may comprise simultaneously sputtering first and second rotating targets, the first target comprising Ag, and the second target comprising Ni and Cr. A magnet bar of the first target may be orientated in a different direction than is a magnet bar of the second target. The magnet bars are respectively oriented so that material to be deposited form the second target is sputtered toward the first target and lands of the first target. The first target may comprise Ag, and the second target may comprise Ni and Cr, for example, or vice versa.
In an example embodiment of this case, there is provided a method of making a coated article including a coating supported by a glass substrate, the method comprising: sputter depositing a first dielectric layer on the glass substrate; sputter depositing a metallic or substantially metallic infrared (IR) reflecting layer comprising silver on the glass substrate located over at least the first dielectric layer; sputter depositing a contact layer comprising Ag, Ni and Cr on the glass substrate located over and directly contacting the IR reflecting layer comprising silver; wherein said sputter depositing the contact layer comprising Ag, Ni and Cr comprises simultaneously sputtering first and second rotating targets, the first target comprising Ag, and the second target comprising Ni and Cr, wherein a magnet bar of the first target is orientated in a different direction than is a magnet bar of the second target so that material to be deposited form the second target is sputtered toward the first target and lands of the first target; and sputter depositing a second dielectric layer on the glass substrate located over at least the first dielectric layer, the IR reflecting layer comprising silver, and the contact layer.